Electrostethograph



NOV. 23, 1937. M, LOCKHART 2,099,938

ELECTROSTETHOGRAPH Filed Feb. 5, 1934 3 Sheets-Sheet l @MMV Mig/f NOV-23, 1937- M. L. LocKHART ELECTROSTETHOGRAPH 3 Sheets-Sheet 2 Filed Feb.5, 1934 .E R .llulllg Y .......flv

ffl/5M Nov. 23, 1937. M. L. LocKHART ELECTROSTETHOGRAPH 3 Sheets-Shea?l3 Filed Feb. 5, 1934 @w114/1,2, ,Zani/kewl Patented Nov. 23, 1937 UNITEDsTATEs PATENT OFFICE on which the movements ofthe galvanometer arevisible and to provide in connection therewith means to show theposition of the highest peaks oi the vibrations so that the amplitude ofthe vibrations can be adjusted to all that come within line 1-1 ofFigure 1, showing the cross section of a microphone cable which I use.

Figure 8 is a-sectional view on the line l-O of Figure 4 showing aconnection between a unit including resistance and condenser elementsELECTROSTETHOGRAPH Marshall L. Lockhart, Des Moines, Iowa ApplicationFebruary 5, 1934, Serial No. '109,797

11 Claims. (Cl. 12B- 2.05)

An object of my invention is to provide an electhe Width of the film orother graph recording? trostethograph or an apparatus of simple,duraelement used. ble and inexpensive construction for graphically Moreparticularly, it is my object in this rerecording heart beats or othervibrations. spect to provide a cylindrical lens adjacent the A furtherobject is to provide an electrostethodeflection screen on which a flashof light will 5 graph of novel construction having means for showwhenever the light reaches the lens, the condensing light rays from alight source and reamplifier of the mechanism being adjustable soflecting them from a reflecting galvanometer that it can then be turnedback until the ash through a cylindrical lens on a lm or other lightdisappears for the purpose of determining the l0 sensitive strip,whereby changes in current afl'ectproper orientation of the deflectionsof the light 10 ing the galvanometer can be graphically recorded beamrelative to the film used in the machine. on the film, means beingprovided for causing the Another object is to provide a novel camera orfilm to travel through the apparatus. other graph recording mechanism.

A further object is to provide a vibration re- Still another object isto provide circuit ar- 15 cording mechanism utilizing a condenser typerangements and controls especially adaptable for 15 microphone forpicking up vibrations, an amplimy apparatus and operable to control itin a maniler for amplifying an electric circuit of the ner especiallyadaptable for the apparatus I dismicrophone and a galvanometer affectedby the close. final output from the amplifier, means being pro- Withthese and other objects in view my inven 2o vided for graphicallyrecording the deilections of tion consists in the construction,arrangement 2O the galvanometer so that thereafter the vibraandcombination of the various parts of my detions or other sound lrecordedcan be accurately vice, whereby the objects contemplated are atanalyzedfor any desired purpose.l tained, as hereinafter more fully set forth,point- More particularly, it is my object to provide a ed out in myclaims, and illustrated in the acmechanism for accurately andgraphically recompanying drawings, in which: 25

, cording the vibrations caused by the action of a Figure 1 is a planIview of a casing with the persons heart so -that a graph of suchvibrations ,mechanism embodying my invention contained can be analyzedby a physician to determine the therein, the lid of the casing beingopened and a exact condition of the heart. microphone and pressure bagof the apparatus Still a further object is to include with the beingtaken from the casing. 30 mechanism,ameans for recording the deflectionsFigure 2 is an enlarged side elevation of a of a sphygmomanometerapplied to a persons portion of the apparatus, as taken for instancepulse so that the pulse as well as the vibrations of on the line 2,-2 ofFigure l, and showing parts the heart are indicated in the graph. ofcasing elements broken away and other parts A further object is toprovide a novel timing of the apparatus in section. 35 mechanism toaccurately mark on the graph re- Figure 3 is a sectional view on theline 3 3 of cording element time periods, regardless of the Figure 2illustrating part of the camera mechaspeed of travel of the graphelement or other nism. factors. Figure 4 is an enlarged sectional Viewon the Another object is to mark on a film or graph line 4 4 of Figure 1illustrating the major por- 4o reCOI'dng Strip Of material, comparatorlines tion of the mechanism of my apparatus and the which enableanalyzation of the graph with rerelation of the parts to each other,spect to comparative amplitudes of the various Figure 5 is a SectionalView on the une 5 5 vibrations, the means for producing the comparaofFlgure 4 showing a plan View of a time wave tor lines being rigid withrespect to the light producing mechamsm 45 source, galvanometer mountingand other parts Figure 6 is a sectional View on the une 5 8 of themechanism so as to eliminate any inaccuof F1 gure 5 showing an end Viewof the mecha; rate departure from the true amplitude of the i f Fi 5vibrations on the graph recording strip. n sm o me ed ti l vi th Afurther object is to provide adefiection screen Figure 7 is an enlargSec Ona ew on e 50 between the microphone and an amplifier' tube of theapparatus.

Figure 9 is a perspective view of a slot forming mechanism used inconnection with a light beam of my apparatus.

Figure 10 is an enlarged sectional view on the line ill-l0 of Figure lillustrating 'the galvanometer used for responding to vibrations.

Figure 11 is a perspective View of a film receiver used in connectionwith the camera part of my device.

Figure 12 is a plan view of a lm or other` graph recording strip usedlfor the purpose of recording vibrations set up in the microphone; and

Figure 13 is an electrical diagrammatic view of the various electricallyenergized parts of my apparatus.

On the accompanying drawings, I have used the reference numeral lil toindicate a suitable casing. A lid il is hinged thereto vand is providedwith a latch or lock l2. The lid ii-is provided with a handle i3 wherebythe casing can be carried from one location to another.

Within the casinglll, I provide a unit A containing the variousapparatuses oi my electrostethograph. v

For convenience. a compartment M is located at one end of the unit A toreceive a pressure bag l5, a microphone l5 (see Figure 1) and a pair ofhead phones Il (see Figure 13) and other loose pieces of apparatus orattachments as may be desired. A door lil is provided for thecompartment it.

The unit A includes a light source, a reflecting galvanometer, thedeflections of which are controlled by the microphone iii and a cameramechanism, all of which will now be described. The light source consistsof an electric light bulb i@ mounted in a socket memberZ (see Figure 4).The light bulb is housed in a primary housing 2l having a removable cap22 which in turn is contained within a secondary housing 33 having aremovable cap 24.

The housing 2| and cap 22 are provided with a light emitting aperture25, while the housing 23 is provided with a light emitting aperture 26.These apertures are located between the light bulb I9 and a galvanometerG.

Interposed between the galvanometer and the light bulb is a lens andslot system including a pair of convex condensing lenses 2l and 23 and apair of slot size defining blades 23. The lens 21 is mounted within alens barrel 33, while the lens 28 is mounted within a lens barrel 3l.The light beam defined by the lines a is condensed by the lens 2l andfocused on the slot defined by the blades 29 whereafter it is condensedby the lens 2li and focused upon the galvanometer G.

The galvanometer may be of any commercially available type and maycomprise briey a permanent magnet 32 having poles 33 and 34 and a coilor loop of current carrying wire 35. The wire 35 has a reflecting mirror36 thereon, the lens 28 condensing the light beam a and focusing itthrough a window 3l onto the mirror 3B. The galvancmeter preferably ischarged with oil 38a or other liquid permitting ultra-violet rays oflight to pass, but preventing the infra-red rays from passing from thelight source to the mirror 36 as the ultra-violet rays only areneeded'for photographic purposes and a clearer graph can thus beobtained, whereas the infra-red rays having diierent reflectioncharacteristics would tend to blur the outlines of the graph.

The rays of light reected from the mirror 36 can be segregated intothree beams indicated by the reference characters b, c and d. The beamsb and d are intercepted by a pair of elongated mirrors arrangedtransversely of the unit A and indicated by the reference numerals 3Band 39. These beams are 'then reflected to fall on a deflection screen4U which may beoi ground glass or the like. At one end of the deflectionscreen, I provide a cylindrical lens 4|, the purpose of which willhereinafter be fully set forth.

'Ihe central beam c reflected from the mirror 38 of the galvanometerpasses between the mirrors 38 and 39, these mirrors being spaced forthis purpose, and falls-upon a cylindrical lens i2 after passing througha transversely elongated aperture 43. U-shaped clips 44 are provided forholding the cylindrical lens 42 in position. l

The cylindrical lens 42 condenses the beam of light c and focuses itupon the sensitized surface oi a strip of film 45. Thus a vertical stripof iight. iconned to such shape by the slot forming blades 29) whenfalling on the mirror 33, will have its ends reflected by the mirrors 3Band 3@ on the deection screen l0 and its central or brightest partpicked up by the lens i2 and condensed to an intensely brillianthorizontal line 0n the lm 55.

It will then be obvious that deflections of the galvanometer coil 35caused by variations and alternations of electric current ilowing'therethrough will result -in laterally swinging movements of the beamsb, c, and d and a consequent visual indication of such swinging of thebeams b and d on the deection screen 40, as well as a graphicrepresentation of such swinging of the beam c on the film 45 when it ismade to travel longitudinally.

For causing longitudinal movement of the lm 45, I provide an electricmotor 46. It is mounted on blocks of sponge rubber 4'! and held down byscrews t8 having resilient bushings 49 interposed between them and themotor so that the vibrations of the motor will not be imparted to thechassis of the unit A and thereby cause vibration of amplifier tubes tobe later described) and thus undesired deflection of the light beams b.c and d. The motor 46 is connected by a belt 50 to a pulley 5l. Thepulley 5l is secured to a shaft 52 having thereon a rubber or otherresilient roller 53. The rubber roller 53 has traction engagement withthey film 135, this being maintained by a-roller 54 which is springurged, as

by springs 55, toward the roller 53. v

' Suitable guides 'and pressure devices are provided for directing thelm 45 between the rollers 53 and 54 and for maintaining the propertension thereon to obtain smooth propulsion of the lm.

The lm itself can be inserted in rolled up lormation in a compartment 56whichv is closed by a sliding light tight plate 51. This plate can beslid upwardly whenever a lid 53 is raised to an out of the way position.

For guiding the lm between the rollers 53 'and 54,' I provide a guideblade 59 curved as at 59a around the roller 53 and arranged in closeproximity thereto. The curved portion 59a. terminates in a plurality ofngers or extensions 6l), the purpose of which will hereinafter bedescribed.

Another guide blade 6I is arranged above the illm, while a resilientpressure spring 62 contacts with the film and presses it toward theguide blade 59. The rubber roller 53 has frictional engagement with thesurface-of the iilm to propel it through the apparatus, while in placeoi' the rubber roller, the ordinary spool with pins around its peripheryto coact with perforations along the side edges of the film may be usedif desired. As a receptor for the fllmafter it passes the lens 42, Iprovide a tubular cylinder-like casing 63. It has a stationary end 84and a removable end 55. A center rod 68 extends from the stationary end64 and is screw threaded as shown in Figure Il to be received in acentral screw threaded opening of the removable end 65. 'I'he cylinderi3 is provided with a slot 8l through which the film may extend into thecylinder.

The cylinder 83 is supported in a compartment 88 which has a slot 68 forthe film to extend through from the roller 53 to the cylinder 63.

Within the cylinder $3 I provide a second cylinder 10 and one isrotatable relative to the other. The cylinder 10 is provided with ahandle 1I extending through a slot 12 of the cylinder 63. The cylinder63 is provided with a lug 13 to enter a socket in the compartment 68 toaline the slot il with the slot 69. The lid 58 is provided with a slot14 through which the handle 1I may project to the outside of the unit A.

The cylinder 10 is provided with a slot 15, the lower edge of which inFigure ll is sharpened. This is for the purpose of cutting oil the film45 when this lower edge coacts with the upper edge of the s'lot 61 whenswinging the handle downwardly in Figure 1l.

Within the cylinder 10 I provide a leaf springr 16 anchored at one end,as at 11, and having its other end free and directed toward the incominglm. The purpose ofthis strip is to permit a considerably longer lengthof film to be pushed into and rolled up within the cylinder l thanotherwise would be possible. It confines the iilm first to a somewhatsmaller diameter and as the motor 46 continues to push film into thereceiver, it expands toward the interior wall of the cylinder 1l! topermit the diameter of the fllm being rolled into the receiver toincrease without undue binding.

A second leaf spring 18 is provided having a guide portion 18a to insurethat the entering end of the lm will be started in the right direction.

The slots 25 and 26 have a downwardly extending portion permitting abeam of light e to pass from the filament of the `bulb I9 to a timingunit T. 'I'his unit consists of an electromagnet 19 (see Figure 5)having pole extensions 80 and 8|. A spring 82 has one end mounted at 83and its opposite end carries an armature 84. An adjusting screw 85 isprovided for the armature. I'he armature fits between arms of the poleextensions 88 and 8l, which are Abifurcated as shown in Figure 6.

The free end of the spring 82 is provided with a mirror 88 whichreflects the beam of light e so that it falls on the lens 42 and isfocused by it on the film 45. Tne timing device T is provided forindicating time periods on the film and for this purpose, alternatingcurrent is used. such current being now almost universally timed toaccurately produce sixty cycles per second. The spring 82 is of theproper mass to vibrate at one-hundred and twenty oscillations per secondso that it is pulled from its normally outer position to an inner dottedline position, as shown in Figure 6, by each rise in the current valueof the alternating current, there being onehundred and twenty such risesper second as there are two rises in alternately opposite directions percycle.

' In Figure 13, I have illustrated a wiring diagram for the variousparts of my apparatus. The microphone i6 is of the condenser type toeliminate the undesired noises usually produced in ordinary carbon typesof microphones because it is my purpose to provide a very sensitiveapparatus which can accurately record graphically the slightestvibration and it will accordingly be undesirable to use a microphonewhich would distort the current impulses from the microphone in any way.Since my apparatus is especially adapted for use by physicians inconnection with the human heart, it will be apparent that the microphonemust be very sensitive and reproduce weak vibrations accurately in orderto accomplish my purpose. v

The microphone has acable I6a which is shown in cross section in Figure'7. The cable Ilia has a wire lib therein and is shielded by a metalliccovering I8c. Between the wire and the covering, insulation iSd isprovided of semihard rubber or the like which permits of sufficientflexibility for the cable without the insulation being so flexible thatit can be compressed when the cable is bent, for instance to such anextent that the wire lsb can move towa'd the shield IBC and thus reducethe capacity between these two members which are the current carryingmembers for the microphone circuit. The wire lh is comparatively smallto reduce capacity as much as possible.

Since the microphone is of condenser type, a change in capacity, ascaused by movement of one of the plates in the microphone in response tovibrations, Varies the current flowing through the wire lb and theshield I6c. Therefore, I provide the cable constructed as in Figure 7 toprevent as much as possible a change in capacity between the conductors18d and Hic.

The microphone circuit includes a condenser 81 and a pair of reslstances88 which are mounted in a shielded casing 89 and the parts 81, 88 and 89constitute a unit which is connected with the grid oi' an amplifier tube90. The connection between'the unit and the grid terminal of the tube 90is made very short and this is accomplished by mounting the unitdirectly over the tube 90, as shown in Figure 8. The tube 90 has ashield 8| and the unit, consisting of the parts 81, 88 and 89, ismounted thereon with a short direct lead 82 from the unit to the gridterminal of the tube 98.

The tube 80 is preferably one of the pentode type in order to getmaximum amplification with a minimum number of tubes. It gives apractical gain of about one-hundred. A second amplifier tube 83 is alsoprovided and it can be of the ordinary triode type. A third tube 94 isprovided which is also `oi' the pentode type. the characteristics of thetubes 90 and 94 differing slightly because of a heat absorption plate 95of the tube 98 being connected exteriorly of the tube with a screen forthe plate therein, while a heat absorction plate 88 of the tube 84 isconnected with the screen for the plate therein interiorly of the tube.AThe tubes 80. 93 and 9L are preferably those designated in the trade as57, "56 and "2A5 respectively. The tube 90 gives a gain of aboutone-hundred, the tube 93 gives a gain of about thirteen, while the tube94 gives a gain of about two-hundred and ten. With this partlcularcombination, (considering loss because of the dimculty of matching thetubes) I can get av 98 has a primary winding and a secondary coilA 99supplying the filaments of the tubes and also the lament of a rectifiertube |00. Another secondarycoil ||l| of the transformer 98 suppliesycurrent to the plates of the rectifier tube and causes a rectifiedcurrent to flow through a tapped resistance |92 from which the platecurrents for the tubes 90, 93 and 94 are obtained and also the currentfor the microphone. I6 and the output transformer 9T in a manner nowwell known.

The transformer 97 is of special construction having an input primarywinding |03 and a pair of output secondary windings |94 and |95.

The winding li is to supply current to the galvanometer G, while thewinding |95 is to supply current to the head phones or loud speaker il.At times an element 06 of high resistance is adapted to be arranged inseries with the head phones il.

I provide for changing the volume of the curv rent supplied to thetransformer 9i by means of an adjustable resistance |01 in the gridcircuit of the tube 9d. This adjusting means includes a switch lever |08associated with a snap switch |99 for cutting off the current supply tothe power transformer 98, the motor lili and a transformer Htl for thetimer T and the light bulb i9, when the parts are in the position ofFigure 13.

When the lever |98 is swung toward the right. a notch therein engagesthe toggle lever of the switch |99 for first moving it to the on"position and then the resistance lill may thereafter be adjusted byfurther movement of the lever 909. An independent control consisting ofa push button il! is provided for the motor M3. The transformer Hi] isof step down type having an output of six volts or so, so that anordinary automobile headlight bulb can be used at i9.

Practical operation Heretofore physicians have determined the |.onditionof a persons heart by means of a stethoscope which somewhat amplies thesound of the heart and by listening through the stethoscope,irregularities of the heart action can be analyzed to some extent. Sincean average heart beat occurs in less than one second, it is quitediiiicult to tell just exactly what is happening. The primary object ofmy invention is therefore to provide a portable apparatus which could besimply operated to produce al permanent amplifed record which could bemade and then studied in minute detail to analyze the heart action withthe utmost accuracy.

In use, the air bag l5 is first placed on a persons upper arm and heldthere by a cloth wrapping l5a. A pump i519 is used for pumping up apressure in the air bagl5 and also in a rubber tube |5c leading to asphygmomanometer S. 'I'he sphygmomanometer is an ordinary pressure gageprovided with an indicating needle ld, such as ordinarily used byphysicians in determining the blood pressure and is characterized in myinvention by having the needle shaftl indicated at H2 -(see Figure 2)extended through the back of the instrument and having mounted thereonareecting mirror H3. The mirror is covered by a glass tube lill andreceives a beam of light I from the bulb i9.

A lens H5 is provided for condensing the light on the mirror ||3 and thebeam f is reected through the lens t2 which focuses it upon the lm andproduces thereon a line such as indicated at B'on the lm shown in Figure12. The lm travels in'the direction of the arrow 45a while the line Band other graph lines on the lm are printed in the direction of thearrow 45h on the film.

In order for the mirrorv i3 to reflect the beam f on the lens 42, thepressure in the bag I5 must be pumped up so that the needle |512 travelsabout half way around the scale, as shown by dotted lines in Figure l.This is the position where most blood' pressure readings are taken andas .the pulse throbs in the arm of the person being examined, the needleld oscillates and swings the beam f so as to produce a line, such as Bon the film shown in Figure 12.

In order to accurately determine that the beam f will follow inside theedge of the film, a portion f of the bea'm f falls upon the mirror 39and is reflected on the deectionscreen all. This screen has thereon aline 40a which corresponds to a line HEC formed on the film l5 by the`lowermost extension in Figure 3.

Since some light is diffused from the left side of the lens Q2 throughthe. lens to the film, this lower extension 6|) prevents light fromfalling on this particular part of the film so that actually thebackground of the film is slightly dark while the line Q50 is a lighterstreak thereon. Whenever positive lm is used, of course the backgroundis light and the line 45e is dark.

The examiner can pump up the air bag l5 until the bar of` light cast onthe deflection screen 4U vibrates across the line 40a so that it is thuspossible by visual means to Idetermine the position that the line B willoccupy on the film.

The next operation is to place the microphone it over the persons heartso that the vibrations,

thereof will be amplied by the tubes 90, 9.3 and 9@ and fed into theoutput transformer 97. These vibrations will thus be transformed intocurrent of varying intensity by variations being above and below acertain current value which normally flows through the primary coil |33when there are no vibrations being imparted to 'the microphone i6 andthis current value being determined by the position of the switch arm mior its knob ltia which is indicated as a deection control on the toppanel of the unit A.

A double pole, double throw switch is provided at H6. In the positionlabeled photograph in Figure 1, this switch will be in its right handposition of Figure 13 and thus the secondary coil |09 will supplycurrent through the switch H6 to the galvanometer G. Also the currentsupply through the switch |09 will now through the switch H6 to thetransformer Illl for operating the timer T and lightingthe bulb i9. Theexaminer can now plug in either a loud speaker or the head phones il ifhe desires, a jack l Il being provided for this purpose. Current fromthe secondary coil |95 will then ow through the resistance element |06and the loud speaker or head phones so that the examiner can' listen tothe heart action as Well as make a graph of it or 0bserve the action onthe deflection screen 49.

The heart action is a pumping action consisting (in a normal heart) of ado-uble beat caused by a first sound or systole followed by a secondAfactors, y the contraction of the ventricular muscles and a suddenstretch of the mitral and tricuspid valves. The diastole is valvular inproduction. Usually the systole will cause a major vibration, while thediastole will cause a minor vibration in the microphone i6 which'will betranslated as increasing the decreasing vibrations in the transformercoil |03.

Since the transformer secondary does not receive current because of thecurrent in the primary being direct current except when such directcurrent is being varied, there will be an induced current in onedirection in the coils |04 and |05 when the current in the coil |03increases above the normal value and an induced current in the oppositedirection when the current in the coil |03 decreases below such value.'Ihis will result in an alternating current in the coil 35 of thegalvanometer G, causing the mirror 36 to be deflected first one way andthen the other. 'I'hese deflections produce on the film 45 a graph lineindicated at C in Figure 12. When the vibrations cease between thesystole and diastole, the line C is comparatively straight, asillustrated, it vibrating slightly. due to inherent vibrations of theapparatus which, by the particular use of pentode tubes, condensermicrophone and the relation of the unit Within the casing 89 to the tube90, have been reduced to a minimum.

When all the parts of the apparatus are properly alined, thenon-vibrating portion of the line C will follow a center line H8 on the'film 45 by the center extension 60 in Figure 3. The lines 45c and i8and other lines I9 are all formedr by the extensions 50 and serve ascomparator lines so that the heights of the peaks of the vibrations ofthe line C can be compared and thus analyzed and successive heart beatscompared with each other or the like. f

d0 The deflection screen 40 has a'line 40h marked thereon and therefiected beams b and d should fall on this line when no vibrations areaffecting the microphone i6 and it is thus-possible to determine whetherthe apparatus is properly alined softhat the non-vibrating portion ofthe line C will fall on the center line i8 of the film in Figure 12.

It will be noted that lthe peaks of the vibrations of=the line C inFigure 12 are inside the side edges of the film. This is caused by thedeflection control knob |0Ba being in a predetermined position. If itwere adjusted to cause greater defiection, the peaks would be higher andvice Versa. It is of course desirable to have them as high as .possiblewithout running'off the edge ofthe film.

I have accordingly provided the lens 4|, which can be observed by theexaminer, so that as he turns the deflection control upwardly he cantell when the beams b and' d strike the lens 4|, as there would be aflash on it caused by the condensation of the light beams and thefocusing thereof on the deflection screen 40. He can then turn thedeflection control backwardly until the flash disappears, whereupon hewill be assured that the peaks of the vibrations yof the line C on thefilm will not extend beyond the side edges of the iilm.

After the examiner has observed the action of the reflected beam f fromthe sphygmomanometer on the deflection screen 40 to make sure that it isin its proper position, has observed the flashing of the beams b and dthrough .the lens 4| on the deflection screen, has adjusted thedefiection cohtrol knohgig tout; proper positionmnd also listened to theheart beats through the head phones I1, if desired, he can cause thegraph to be made on the film by merely pressing the push button whichstarts the motor 46 and causes the film 45 to travel into the receptorcylinder 63, as shown in Figure 4. During its passage into the receptor,the graph will be rnade and also timing lines |20 will be impressed onthe film by the vibrating reflected beam e. 'I'his line |20 is producedas a diffusion from a series of V-shaped lines |2i which are actuallyone half of a vibration, the other half falling as at |22 ofi' the edgeof the nlm.

As the lm moves forward at a constant speed and the'tirner T oscillatesin accordance with the alternating current cycles, the V-shaped marks|2| will be produced and the peak of the V is extended because o1'diffusion through the cylindrical lens 42, as indicated by the lines|20. These lines gradually fade out but nevertheless appear as lines, orrather on a negative film, dark streaks which are one-hundred twentiethof a second apart and thus provide a means for analyzing the heartaction and show just what happens each one-hundred twentieth of asecond.

After four or five seconds, the push button IH can be-released and afilm showing graphically six or seven heart beats and pulse actions willhave been produced. The handle must then be swung to the dotted lineposition of Figure 4 for cutting ofi the film and closing the cylinder63 so that the cylinder can be removed from the compartment 68 and takento the dark room for development.

The lid 58, of course, must be opened to remove the cylinder and I havepreferably provided the slot `|4 of such length that the lid cannot beopened until the handle l| is swung to the .remove position of Figure 1to thus in# sure that the film will be cut off and closed in thecylinder v63 before the cylinder is removed.

After development, the 'film may appear somewhat as in Figure 12. Thisis a reproduction of a sample actually taken with my machine and is ofan abnormal rather than a normal heart. It will be noted that there is avibration C in the line C and this should not be, or in other words, thenon-vibrating portion of the line C should extend `all the way to theleft hand end of the film in Figure 12 (the film representing one heartbeat) if it were for a normal heart.

The amplitude of the Vibration C determine accurately whether the intakeor outlet valve leaks, or what other trouble is present as well as theseriousness of the trouble, which is indicated by the amplitude of thevibration C' with respect to the major and minor normal vibrations.

In different hearts, the spacing between the major and minor vibrationsvaries and without the pulse wave B, it would sometimes bedifiicult todetermine just which is the intake and which is the outlet stroke of theheart,hence one reason for producing the line B as well as the line C onthe film.

With relation to the major vibration of the line C, it will be notedthat the pressure increase, indicated by the hump in the line B, fallsdirectly thereafter, indicating that the major vil bration was thesystole and the pulse in the arm received the increase in pressure abouta twentieth of a. second after the completion ofthe systole. amplitudeof the hump in the line-Rafa Y is also thus graphically and permanentlyreand its po-J sition with respect to the major and minor' vi'- fbrations can now be analyzed by the physician tov corded along with theheart action, as shown by the line C.

Although I do not know all the possibilities and advantages to bederived from such an accurate graph of the heart and pump action, I havestated generally some of the things that can be expected and it will beobvious that a very accurate analyzation can be made b` a `study of thegraph and that there is a chance for advance in heart study byphysicians who will devote time to i'lnding out what else can be learned-from the comparison of a number of graphs of different persons with thestethoscope method of analyzaton now in use.

If the examiner desires to only listen to the heart action, the switch||6 can be swung to the left hand position in Figure 13 for shorting outthe resistance element i |16 so that the entire value of the current inthe coil can opcrate on the head phones i1 or on a loud speaker. Thisopens the circuit of the coil |04 so that the galvanometer does not takeany current and also Opens the circuit to the motor 46 so that it cannotbe accidentally energized and film thus wasted, the circuit to thetransformer im being broken by the switch i it in its left hand positionto de-energize the timer T and the light bulb I9.

Heretofore, light beams reiiected from a galvanometer have requiredapparatus which is strung out over' a comparatively long distance. Bythe use ofthe condensing lenses 21 and 28 and their particular relationto each other, to the bulb i9 and to the galvanometer G and also theposition and relation of the slotv forming blades 29, I haveconsiderably condensed my apparatus so that it can be convenientlymounted in compact form, the actual apparatus I have constructed beingless than twice the actual size shown on the drawings in Figure 4. Ihave also provided adjustments for the various parts of lthe apparatuswhich can be quickly made Without great skill and which I will nowdescribe.

The lens barrel 3|) is mounted on a yoke |23 pivoted at IN. The barrelitself is pivoted at |25 to the yoke and has an varm |26 which can beadjusted up or down by a set screw |21, thus tipping the barrel up ordown. A similar set screw |28 coacts with an arm |29 extending from theyoke |23 for swinging the barrel 30 laterally. Thus the axis of thebarrel can be alined with the galvanometer mirror 361 The lament of thebulb i9 can be alined with the axis of the barrel by loosening a clampscrew |30 of a clamp bandl|3| and sliding the socket member 20 up ordown. The inner casing 2| around the bulb I9 and the clamp band |3| canbe adjusted toward or away from the barrel and also laterally byloosening screws |32 extending through enlarged openings of thestationary outer casing 23.

This is for the purpose of getting the filament' of the bulb I9 theproper distance from the lens 21 so that the lens will focus the lightbetween the slot forming blades 29. The lens barrel 3| is screw-threadedin the barrel 30 so as to adjust the lens 28 longitudinally of thebarrel Bil,A and thus lfocus the light from the slot on the galvanometermirror.

'I'he slot forming blades 29 are carried by blades 29a extending from aring 291).`

The width 0f the slot between the blades 2@ can be adjusted by setscrews |33 (one inserted in each side of the barrel 3|!) while the ring29h can be adjusted up or down by set screws |34 which pivotally supportit. Looped spring-like connectors |35 are provided for the slot foriningblades 2li so as to normally spread them and keep the blades 29a againstthe set screws |33.

The galvanometer G is pivoted at |36 and can be adjusted to swingthereabout by an adjusting nut |31. This tips the reflected beam oflight up or down so as tov throw it on the lens l2 and equally on themirrors 38 and 39. The galvanometer poles 33 and 3d and the casingelement Ma are moimted as a unit to pivot on a pivot pin |38 so as tothrow the reflected beam toward one end or the otherof the lens l2 andaline it with the line 40h on the deflection screen. The deflectionscreen M) is a ready means to facilitate checking the variousadjustments of the apparatus. The beams b and d falling thereon can beobserved and if one is brighter than the y other, it indicates that thegalvanometer G is tipped up or down a little too far. Both should havethe same brilliancy and be brighter along their adjacent edges thanalong the edges which strike the left and rear edge of the deflectionscreen`in Figure 1 in order for the most brilliant portion of thereflected beam a to pass as a beam c between the mirrors 33 and 39 to beutilized for tracing the graph line C on the film t5.

When adjusting the lens barrels 3|! and 3| and also the slot adjustingset screws |33, a dark card or the like can be placed in front of thegalvanometer lens 31 so that the beam of light a will fall thereon whilemaking the adjustments. The character and position of the spot of lighton the card can be observed while the adjustments are made and theproper position of the light I9 can be ascertained by the same means.

Although I have shown a lm as a means for graphically recording theheart beats, other strips of material may be used and graph producingmechanism other than a light beam can be af- 'iected by the galvanometerto produce a graph thereon. A timer in the form of a vibrating pin toprick perforations in the graph recording material can be used insteadof the timer T and these changes as well as others may be made withoutdeparting from the real spirit and purpose of my invention, and it is myintention to cover by my claims, any modified forms o f structure or useof mechanical equivalents, which may be reasonably included Within theirscope.

I claim as my invention:

1. In an electrostethograph, a casing, an electric bulb therein, agalvanometer in the `path of light therefrom, a illm reception housingwithin said casing, said casing having a lm compartment, a roll ofiilmvtherein, a roller engaging said film for propelling it, means forrotating said roller, a controller for said means, a lens adjacent saidroller and between the illm and the galvanomete'r for concentratinglight from the galvanometer on the film, said roller upon rotationcausing said film to leave said illm compart ment, pass said lens andenter said lni receiving housing, a microphone, an amplifler foramplifying the output of said microphone, said microphone beingconnected with the input of said ampliiler and the output of saidamplier being connected with said galvanometer whereby vibrations pickedup by the microphone are recorded on the i'llm when said means is inoperation as a result of operating said controller and a common sourceof current supply for said electric bulb, galvanometer and amplifier.

2. In an electrostethograph, an electric microphone for picking up heartsounds, an electric circuit therefor, an amplifier for said electriccircuit, movable means responsive to pulse pressure changes, a recordingelement, means for propelling said recording element, iirst meansresponsive to the output of said amplier and second means operable bysaid pressure change responsive means for simultaneously graphicallyrecording the amplitude of the output from said amplifier and therebythe sounds from the heart and the movements of said pressure changeresponsive means on said recording element.

3. In a device for detecting and graphically recording heart sounds, asound detecting mechanism, a recorder for the detected sounds includinga recording element on which a graph of the sound picked upvby saidsound detecting mechanism is graphically recorded, pulse responsivemechanism, means for graphically recording the pulse action on saidrecording element simultaneously with the recording oi said detectedsounds thereon, means for adjusting' the position of the pulse recordingon the recording element with relation to the sound recording thereonand means for visually indicating the excursions of the pulse recordingmeans to determine such relative positions.

4. In an electrostethograph, a graphic recording device including agalvanometer and a recording element, a microphone responsive to heartsounds of a living being, means for recording the heart sounds on saidrecording element, means responsive to the pulse waves of the livingbeing, said last means including a movable element for recording thepulse wave action on said recording element simultaneously with therecording of heart sounds, said microphone being electrically connectedwith said galvanometer to actuate it in response to such heart soundsand means to audibly indicate such'heart sounds simultaneously with therecording thereof and the recording o1' the pulse wave action.

V5. In a device for detecting and graphically recording heart sounds, asound detecting mechanism, a recorder for the detected sounds, a pulseresponsive mechanism, means for graphically recording the pulse actionon said recorder simultaneously with the recording of said detectedsounds thereon, means for changing the amplitude of the recorded' soundsand the position of the pulse action recording on said recorder andfmeans for visually indicating the excursions of the sound detectingmechanism and the pulse recording means whereby to determine and correctthe amplitude of the recorded sounds and position of'the pulse actionrecordings on the recorder.

6. In an electrostethograph, the combination oi.' an electric microphonefor picking up heart sounds, an electric circuit therefor, an ampliiierfor said electric circuit, a recorder for recording the output of saidampliiier. said recorder including a galvanometer, control means toeil'ect operation of sa'id recorder, control means for controlling theamplitude ot the current supplied to said galvanometer, and means foralso translating the output of said ampliiier into audible sound waves.l

7. In an electrostethograph, the combination of an electric microphonefor picking up heart sounds, an electric circuit therefor, an amplifierfor said electric circuit, a recorder for recording the output of saidamplier, said recorder including a galvanometer, control means to eifectoperation of said recorder, control means for controlling the amplitudeof the current supplied to said galvanometer, and means for alsotranslating the output of said amplifier into audible sound waves, andfor indicating visually the amplitude of the galvanometer vibrations.

`8. In an electrostethograph, amplifier mechanism, a microphoneresponsive to heart sounds and electrically connected with the input ofsaid amplier mechanism, means electrically connected with the output ofsaid amplifier to translate electric vibrations therefrom into soundwaves, pulse responsive mechanism, a visual indicator for pulse wavesconnected 'therewith and actuated thereby, said microphone and pulseresponsive mechanism being simultaneously applicable to the cardiacregion and the pulse of a patient whereby to visually indicate the pulsewaves and simultaneously therewith audibly indicate the heart sounds.

9. In an electrostethograph, amplifier mechanism, .a microphoneresponsive to heart sounds and electrically connected with the input ofsaid amplifier mechanism, means electrically connected with the outputof rsaid amplifier to translate electric vibrations therefrom into soundwaves, means electrically connected with the output of said amplifier totranslate electric vibrations therefrom into visual vibrations, pulseresponsive mechanism, a visual indicator for pulse waves connectedtherewith and actuated thereby simultaneously with and adjacent thevisual vibrations indicated by said means, said microphone and pulseresponsive mechanism being simultaneously applicable to the cardiacregion and the pulse of a patient whereby to visually indicate the pulsewaves and simultaneously there- .'with audibly and visually indicate theheart sounds.

10. In a device of the class described, graphic recording mechanismincluding a light beam, a viewing screen for said light beam and meansfor indicating excessive vibrations of the light beam across saidviewing screen comprising a light condensing lens adjacent the end ofthe screen in position to be in the path oi' the light MARSHALL L.IDCKHAD'

